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| author | Vasily Gorbik <gor@linux.ibm.com> | 2019-11-25 15:34:59 +0300 |
|---|---|---|
| committer | Vasily Gorbik <gor@linux.ibm.com> | 2019-11-30 12:52:47 +0300 |
| commit | 4ac24c092b4eef69b2436ee4d478500dc886e8b5 (patch) | |
| tree | e313e5c73958572c5a3266c0597932aea9403db2 | |
| parent | f44fa79b104b56d53d33ae43e69bab98b63d4783 (diff) | |
| download | linux-4ac24c092b4eef69b2436ee4d478500dc886e8b5.tar.xz | |
s390: fix register clobbering in CALL_ON_STACK
CALL_ON_STACK defines and initializes register variables. Inline
assembly which follows might trigger compiler to generate memory access
for "stack" argument (e.g. in case of S390_lowcore.nodat_stack). This
memory access produces a function call under kasan with outline
instrumentation which clobbers registers.
Switch "stack" argument in CALL_ON_STACK helper to use memory reference
constraint and perform load instead.
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| -rw-r--r-- | arch/s390/include/asm/stacktrace.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/s390/include/asm/stacktrace.h b/arch/s390/include/asm/stacktrace.h index 4725315a9cb1..ee056f4a4fa3 100644 --- a/arch/s390/include/asm/stacktrace.h +++ b/arch/s390/include/asm/stacktrace.h @@ -112,12 +112,12 @@ struct stack_frame { \ asm volatile( \ " la %[_prev],0(15)\n" \ - " la 15,0(%[_stack])\n" \ + " lg 15,%[_stack]\n" \ " stg %[_frame],%[_bc](15)\n" \ " brasl 14,%[_fn]\n" \ " la 15,0(%[_prev])\n" \ : [_prev] "=&a" (prev), CALL_FMT_##nr \ - [_stack] "a" (stack), \ + [_stack] "R" (stack), \ [_bc] "i" (offsetof(struct stack_frame, back_chain)), \ [_frame] "d" (frame), \ [_fn] "X" (fn) : CALL_CLOBBER_##nr); \ |